This is a day and hour countdown timer module with external connection for power source, keys, and output poles. The capacity is 99 days 23 hours. 16 mm digit height countdown timer module with 4 special options as the paragraph of feature indicated below. The external connection pads are at both edges of PCB. 5 output poles with different waveform for special application are available upon request. Many kinds of counting capacity are available too. Under special request, it is possible to program the timer to fix the counting interval to a certain value to measure the lifespan of any durable devices, such as filter, UV lamp, or to manipulate other electronic device.